After departure from newark, my aircraft suffered a loss of radio communication with ny departure control. I was unable to establish radio contact with departure after the handoff from newark tower. Our first action was to maintain the departure instructions issued to our flight by ATC and secondly to try and re-establish radio contact with ATC. I determined the problem to be in the aircraft's #1 VHF communications radio. The radio box had malfunctioned and created the same problem that a stuck microphone button creates. A near complete blockage of the selected frequency. To overcome the situation, my first officer switched our #2 VHF communication radio to the standard emergency frequency 121.5 and quickly re- established communications with new york departure who then assigned us a new departure frequency. While the first officer handled the communications, I disabled the #1 communication radio and cleared the 'stuck microphone' condition. ATC then vectored us away from a potential traffic conflict and returned our flight to a normal departure track. The negative aspects of this event are as follows: 1) during the event we were in IMC conditions at a low altitude on a vector from ATC that would have eventually taken us towards rising terrain and other manmade obstructions. 2) during the period of lost communications, our flight did not maintain standard minimum separation from another IFR departure from morristown airport, to the west of newark. While no 'near miss' was involved, the loss of separation made the event 'reportable.' our original clearance was via the newark four departure. The change to our departure instructions came as we were taking the runway. The vectored departure is one favored by most of the regional carriers as an expeditious procedure. I personally feel it may be occasionally inappropriate when the ceiling is below the initial assigned altitude of 2000 ft MSL. Had we not been issued the vector and been allowed to follow the published departure as we were originally assigned, we would have been in a far better position to execute a precise lost communication procedure in the event we were unable to re-establish contact with ATC.

Title: ON DEP FLC LOST COM, LOST STANDARD SEPARATION, IMC, USED 121 POINT 5 RE-ESTABLISHED COM WITH TRACON ON ANOTHER TRANSCEIVER AND WAS VECTORED CLR OF TFC.

Narrative: AFTER DEP FROM NEWARK, MY ACFT SUFFERED A LOSS OF RADIO COM WITH NY DEP CTL. I WAS UNABLE TO ESTABLISH RADIO CONTACT WITH DEP AFTER THE HDOF FROM NEWARK TWR. OUR FIRST ACTION WAS TO MAINTAIN THE DEP INSTRUCTIONS ISSUED TO OUR FLT BY ATC AND SECONDLY TO TRY AND RE-ESTABLISH RADIO CONTACT WITH ATC. I DETERMINED THE PROB TO BE IN THE ACFT'S #1 VHF COMS RADIO. THE RADIO BOX HAD MALFUNCTIONED AND CREATED THE SAME PROB THAT A STUCK MIKE BUTTON CREATES. A NEAR COMPLETE BLOCKAGE OF THE SELECTED FREQ. TO OVERCOME THE SIT, MY FO SWITCHED OUR #2 VHF COM RADIO TO THE STANDARD EMER FREQ 121.5 AND QUICKLY RE- ESTABLISHED COMS WITH NEW YORK DEP WHO THEN ASSIGNED US A NEW DEP FREQ. WHILE THE FO HANDLED THE COMS, I DISABLED THE #1 COM RADIO AND CLRED THE 'STUCK MIKE' CONDITION. ATC THEN VECTORED US AWAY FROM A POTENTIAL TFC CONFLICT AND RETURNED OUR FLT TO A NORMAL DEP TRACK. THE NEGATIVE ASPECTS OF THIS EVENT ARE AS FOLLOWS: 1) DURING THE EVENT WE WERE IN IMC CONDITIONS AT A LOW ALT ON A VECTOR FROM ATC THAT WOULD HAVE EVENTUALLY TAKEN US TOWARDS RISING TERRAIN AND OTHER MANMADE OBSTRUCTIONS. 2) DURING THE PERIOD OF LOST COMS, OUR FLT DID NOT MAINTAIN STANDARD MINIMUM SEPARATION FROM ANOTHER IFR DEP FROM MORRISTOWN ARPT, TO THE W OF NEWARK. WHILE NO 'NEAR MISS' WAS INVOLVED, THE LOSS OF SEPARATION MADE THE EVENT 'REPORTABLE.' OUR ORIGINAL CLRNC WAS VIA THE NEWARK FOUR DEP. THE CHANGE TO OUR DEP INSTRUCTIONS CAME AS WE WERE TAKING THE RWY. THE VECTORED DEP IS ONE FAVORED BY MOST OF THE REGIONAL CARRIERS AS AN EXPEDITIOUS PROC. I PERSONALLY FEEL IT MAY BE OCCASIONALLY INAPPROPRIATE WHEN THE CEILING IS BELOW THE INITIAL ASSIGNED ALT OF 2000 FT MSL. HAD WE NOT BEEN ISSUED THE VECTOR AND BEEN ALLOWED TO FOLLOW THE PUBLISHED DEP AS WE WERE ORIGINALLY ASSIGNED, WE WOULD HAVE BEEN IN A FAR BETTER POS TO EXECUTE A PRECISE LOST COM PROC IN THE EVENT WE WERE UNABLE TO RE-ESTABLISH CONTACT WITH ATC.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.